Thermoelectric alarm



UNITED STATES PATENT omen.

ABILIO M. DE SILVA GREAVES, OF CAMBRIDGE, MASSACHUSETT THERMOELECTRIC ALARM.

' Specification of Letters Patent.

Patented Feb. 14, 1922.

Application filed July 17, 1919. Serial No. 311,477.

State of Massachusetts, have invented new and useful Improvements in Thermoelectric Alarms, of which the following is a specification.

This invention relates generally to thermoelectric alarms, the invention being adapted particularly for use in connection with the cooling systems of combustion engines.

The primary object of the invention is to provide an alarm system including means of an improved andsimplified nature for application to the radiator cap of a motor vehicle for closing a circuit through the alarm system when the temperature of the water employed as a cooling medium reaches a predetermined degree.

The invention consists 'of the features of construction, combination and arrangement of parts hereinafter fully described and claimed, reference beinghad to the accompanying drawing, in which:

-Figure 1 is a vertical section of the circuit closing device aslit appears when applied to the radiator of a motor vehicle.

Figure 2 is a perspective view of the device removed from its outer casing and showing the upper cap retnoved.

Figure 3 is a transverse sectional view on line 33 of Figure 1.

'Figure 4.- is a bottom plan view of the cap member employed for securing the lower ends of the separable sections of the body or inner casing together.

Figure 5 is a top plan View of the contact base.

Figure Gris a diagrammatic view of the alarm system in its entirety.

Referring now more particularly to the drawing, 7 and 8 represent respectively the separable parts of a body or inner casing formed of suitable insulating material, such as baked clay, porcelain or the like, the body being ofany desired shape, or octagonal as shown, when the said sections are placed together in proper position. This body is of a diameter substantially equal to that of the nipple 9 of the motor vehicle radiator. The

two-part body is adapted to contain a mercury tube 10, having its lower end provided w th the enlargement or bulb portion 11 within which the mercury is contained, and the upper end of the tube is enlarged as at 12 to provide an expansion chamber into which the mercury column enters when the column ascends under the influence of heat.

The upper end of the chamber 12 of thethermo member is, closed by a cap or cover member 13 formed of suitable insulating materlal, the said cap member being preferably of-a dlameter equal to the transverse diam eter of enlargement 12. This cap member carrles a depending member 14 which extends centrally into the chamber 12, and the terminals 15 of electric conductors 15 are arranged one upon each side of this depending portion. The conductors extend upwardly through the cap member 13 and then downwardly through suitable channels or grooves provlded upon the abutting faces of the two-part sections 7 and 8, and connected at their lower ends with contact members 16 arranged as hereinafter described. The restricted column or tube 10 snugly fits within a recess formed by providing central longitudinally disposed cooperating channels upon the abutting faces of the two-part body 7 and 8, and these channels are enlarged at their upper ends so as to accommodate and snugly receive the enlarged portion 12 of the mercury column and alsothe cap member 13. It will be observed that the cap member is provided with an annular flange 17, to seat in suitable grooves or recesses formed in the two-part body members, and it will be understood that this annular rib or flange prevents the cap member becoming detached from the body when the parts of the latter are properly assembled over the said cap. The lower ends of the two-part sections are cut away so as to provide a chamber or space 18 into which the bulb portion 11 of the column or tube extends, and it will be noted that the chamber is appreciably larger than the diameter of the bulb. The upper and lower ends of the cylindrical insulating body are closed by the remouable caps 19 and 20, which caps are threaded upon reduced portions of the body as shown.

The upper cap 19 forms a closure for the upper extremity of the insulating body and protects'the cap member 13 and the conductors 15 extending out of the same, while the lower cap 20 adequately houses the mercury bulb l1 so as to protect the same and yet permits of the free passage of air or-vapor thereto through the openings 21 formed in the said cap. 'The sections constituting the two-part body are also held in proper assembled position by the dowel pin or projections 22 carried by one of the said sections and projectinginto the other. A guard or shield 23 of wire gauze or like material surrounds and reinforces the bulb 11 and protects the same from fracture under vibrations of the vehicle;

The insulating tube carrying body or 1nner casing thus constructed and assembled is housed within a casing indicated at 24, the latter having an interior diameter equiv.-

alent to the exterior diameter of the twopart body so as to snugly enclose the latter, and this housing projects at its lower end beyond the lower extremity of the two-part body and is interiorly threaded as shown to be screwed upon the nipple 9 of the radlator of the vehicle. The two-part body and the hood member or covering 24 thereof are used in lieu of the radiator cap now employed to close the nipple, and it will be understood that upon tightly screwing the member 24 upon the nipple 9 a substantially air tlght closure is provided. This cover member 24 is preferably made of metal, closed at its upper end, and has its lower open end thickened or expanded and made externally of angular form for the application of a Wrench 01' similar tool, whereby said cover member may be applied to and removed from the nipple 9. The part 25 is provided with pas- The contacts 16 are adapted for engagement with contact 26 carried by an insulated base ring 26' and connecting with conductors 27 "and 28 forming part of an electric circuit shown in Figure 5,,which circuit includes an audible signal such as a buzzer or hell.

29. This circuit may be supplied with elec, tric energy from the magneto of the combustion engine or the spark or lamp circuits, or

it may be a separate and distinct circuit having its own source of electric energy such as the battery-30. The cap 20 is engaged by a ring or gasket 31 sprung into the internal groove or recess in the member 24, whereby the innercasi'ng and thermostatic device carried thereby are held in position within the outer casing 24 against displacement, the construction being such however that by electric circuit.

' bottom of the cap sages alining at their upper ends with the springing the ring 31 out of the groove such parts may be disconnected. Suitable tools or other means may be employed for threading the lower ends of the conductors 15 through the part 25, as shown, and the lower ends of the conductors may be severed whenever it is desired to disconnect the component parts :of the device; orwmy suitable sectional construction of the conductors may be employed to permit application and removal of the internal casing and thermostatic device without disturbing the lower portions of the conductors or the contact 16. The conductors 27 and 28 extend through a tube 32 which projects down into the radiator, said tube being of T-form or having branching arms 33 through which the terminals of the conductors extend outwardly through the radiator casing to the contacts 26.

The device so constructed is assembled with the mercury column arranged within the two-part inner casingin the manner shown. The parts of the casing are then secured together by applying the caps 19 and 20 thereto, after which the inner casing and its parts are fitted within the outer casing and secured therein in the manner described, the lower ends of the conductors 15' being suitably connected with the contacts 16. The device in its entirety is then applied to the nipple of the radiator, and when the outer casing has been screwed down to its lowest limit, the contacts 16 will engage the contacts 26 and electrically connect the thermostaiiic device with the terminals of the The air or vapor arising from the water within the cooling system of the radiator may have free access to the mercury bulb 11 through the openings 21 in the Should the water in this cooling system become heated to such a degree as to cause the vapor or steam arising therefrom to expand the mercury within the mercury column 10 so as to enterthe chamber 12 and bridge the ends of conductors-'15, the circuit of the alarm system will be closed, whereupon the bell or buzzer 29 will be sounded. Cooling ofthe water within the radiator will permit the mercury to contract, whereby the circuit will be broken. When it is desired to have access to the interior of the radiator, for the purpose of replenishing the water supply, the cover member 24 and its asso-- 'eiate'd parts may be readily removed in the same manner as is the commonly used radiator cap.

The various parts of the device which constitute 'the cover member and its'associated parts are simple and inexpensivb of construction, may be easily and quickly assembled, are held together in a manner such as to minimize the opportunity for breakage or dismemberment, and the conductors -cardescribed my invention,

' to a radiator.

2. In a thermostatic alarm device, a twopart body having an open portion at one end, thermostatic circuit closing means in said body, .the said thermostatic means extending into said opening, means for securing said body parts together, and a' shell enclosing said body and adapted to be secured to a radiator so that the said 0 ening will be in direct communication with the interior of the radiator.

3. In a thermostatic alarm device, a body of insulating material having an open portion at one end thereof, a thermostat carried by the body and having a globe portion disposed within said open portion, a foraminous cap closing said open portion, means for attaching said body to the body of a radiator, and means governed by the thermostat for closing a circuit.

4. In a thermostatic alarm device, a twopart body, a thermostat arranged within said body, a cap member carried by said body and closing the upper extremity of said thermostat, conductor terminals extending through said cap and into said thermometer and maintained in spaced relation, a cover member enclosing said two-part body and adapted to be attached to a radiator body, and means for connecting the said conductors to the terminals of an electric circuit. 1

' 5. In a thermostatic alarm device, a body, a thermostat within said body, the said thermostat being open at its upper end, a cap member closing said open end, a depending member on said cap extending into-said thermostat, conductors'carried by the body and having the terminals thereof extending, through said cap one upon each side of said depending member and spaced from each other, a cover member enclosing said body and extending beyond the same at one end, electric conductors carried by said cover member, the said terminals adapted to be electrically connected with the conductor members of the body, and means whereby the cover member conductor members may be electrically connected with a signal circuit.

' 6. In a thermostatic alarm device, a twosaid body and being longer than the latter, means whereby said cover member may be attached toa radiator body, a member carried by said nipple and having contact members thereon, conductorscarried by the cover member and engaged at one end with said contactmembers, conductors carried by the body and having their lower ends in electric connection with the conductors of said cover member, the opposite ends of said body conductors being disposed in spaced relation within said thermostat, and the contact members on said nipple carried member being connected with the terminals of an electric circuit. 7. In a thermostatic circuit closer, supply circuit terminals adapted to be' mounted upon an automobile radiator, a thermostat including a shell adapted to be r'emovably attached to the body of the radiator, and circuit contacts in said shell for engagement with the first named contacts and adapted for connection to close a circuit under the action of said thermostat at a predetermined temperature. 7

, 8. In 'a thermostatic circuit closer adapted for use with an automobile radiator having an opening therein, a thermostat including an enclosing shell withacap portion adapted to be fitted upon and to form a closure for said radiator opening, circuit contacts adapted to be disposed upon the radiator, and circuit contacts within the shell and engaging said first-named contacts, said second-named contacts being connected with conductors extending through the'cap and adapted to be electrically connected by the thermostat'for closing a circuit at a predetermined temperature.

9. In a thermostatic circuit closer, for use in connection with an automobile radiator having a nippled opening therein, a thermostat including a shell having an integral part adapted for engagement with the nipple so as to form a closure for the opening thereof, and circuit contacts adapted to be connected by said thermostat at a predetermined temperature.

10. In a thermostatic circuit closer for use in connection with an automobile radiator having an opening therein, a body adapted to be attached to the radiator to form a closure for the opening, a thermostat enclosed within said body, and circuit contacts for a normally open circuit adapted to be connected by said thermostat for closing the circuit at a predetermined temperature.

I 11. In a thermostatic circuit closer, for use in connection vwith an automobile radiator having an opening therein, a two-part body, a shell enclosing said body and adapted to be attached to the radiator to form a closure for the opening, a thermostat disposed withopening and resting on said member and having circuit contacts complemental to said first-mentioned circuit contacts, and a thermostat Within said body operative to close the circuit through said circuit contacts at a predetermined temperature.

In testimony whereof I afiix my signature.

ABILIO M. DE SILVAGREAVES; 

